In everyday discourse, we often draw a distinction between actions that are performed intentionally (e.g. opening your car door) and those that are performed unintentionally (e.g. shutting a car door on your finger). This distinction has interested philosophers working in a number of different areas. Indeed, intentional actions are not only the primary focus of those concerned with understanding and explaining human behavior, but they often occupy center stage in philosophical discussions of free will and moral and legal responsibility as well. And while most philosophers agree that the distinction between intentional and unintentional action plays an important role in our folk psychology, there is still wide-scale disagreement about the precise nature of this role. Until recently, there has been a lack of empirical data about the folk concept of intentional action and as a result the debate among philosophers has been mostly